In the prior art, a WI-FI device includes an Access Point (AP) working mode and a Station (STA) working mode. When a WI-FI device works in the AP working mode, the WI-FI device must have a Dynamic Frequency Selection (DFS) test. When a WI-FI device works in the STA working mode, the WI-FI device does not need to have the DFS test. DFS is a mechanism that allows unlicensed WI-FI devices to share a spectrum with existing radar systems (for example, weather radars at or near airports). A WI-FI device must scan channels sufficiently to determine whether a radar exists. If the WI-FI device working in the AP working mode detects the radar, the WI-FI device must drop the channel within a designated time.